Diamond turning machine for forming pistons of elliptical shape



.lune 28, 1938. l J. sNADER ET AL 2,121,934 DIAMOND TURNING MACHINE FOR FORMING PISTONS OF ELLIPTICAL SHAPE Filed Feb. 25, 1935 a shams-shem-l 1 INVENTRD- ORNEYS- 2,121,934;y DIAMOND TURNING .MACHINE Non FORMING PIsToNs o ELLIPTICAL SHAPE June" 2 8, 1938. J. sNADER ET AL Filed Feb.' 2s, v1935 a sheds-sheet 2- June 28,v 1938. l'. J.' sNADER Erm. 2,121,934 DIAMOND TURNING MACHINE FOR lFORMING PISTONS OF ELVLIPTNICAL SHAPE' I Filed Feb. 23, 1955 8 She'etS-Sheet 3 RNEYS.

June 28, 1938.

DIAMOND TURNING MACHINE FORNORMING PIsToNs oF 'ELLIPTICALLSHAPE Filed Feb. 23,1955 s sheets-sheet 4 i A15-E1 44 INVENTORS- fm J." Shader Chr-:Sivan /lr//ebaic ,BY @14M 9 TORNEYS- June 28, 1938. l'. J. sNADER ET Al. 2,121,934 DIAMOND TURN-ING MACHINE FOR FORMING PISTONS OF ELLIPTICAL SHAPE Filed Feb. 2s, 1935 8 sheets-sheet 5 INVENTORS.

'Bf/muffa Mair/@zaak MMM/f June 28, 1938.V y l SNADER ET AL' 2,121,93411 DIAMOND TURNINGv MACHINE FOR FORMINGPISTONS O ELLIPTICAL SHAPE Filed Feb. 23, v1935 8 Sheets-Sheet 6` A oRNEYs.

lJune 28, 1938. l. JjsNADER ET AL i 2,121,934 DIAMOND TURNING MACHINE AFOR FORMING PISTONS OF' ELLIPTICAL SHAPE' Filed Feb. 2s'. 1935 s sheets-sheet 'rV ORNEYS.

-Junezs,193s. -LflsNA'DERAL 2,121334 DIAMOND TRNING MACHINE FOR FORMING lPISTQNS OF ELLIPTICALLHAPE ATTORNEYS.

Patented June 28, 1938l DIAM oNn TURNING mcnnm ron. roaM- i rNc ris'roNs or mmr'rlcsn sans A Ira J. Snader and Christian A. Birkebak', Detroit,

Mich., assignors to Ex-Cell-O Corporation, a corporation of Mlollllan Application February 23, 1935,

serai No. 'was Fig. 12 isa top plan view of a machine having This invention relates to amachine for shaping or turning internal combustion motor pistons'and thelikep The main objects of this invention are to pro- Vide an improved machine for turning pistons and the like to an elliptical cross-sectional shape; to provide a machine for turning a piston or like workpiece to slightly helical shape in`an axial direction; to provide a machine for tin-ning a piston having an elliptical shape at anycrosssection normal to the longitudinal' axis of the piston but with the maior axes of such elliptical cross-section shifting to diiIerent rotational positions along the piston, and to provide as machine of this character which can be readily adjusted to vary the shape of the piston or'the like being turned. An illustrative embodiment of this invention is shown in the accompanying drawings.' in which: Fig. 1 is a view in perspective of the improved machine.

Fig. 2 is an` enlarged fragmentary transverse vertical sectional view of the same taken on the line 2--2 of Fig. 1, looking in the direction indicated.

Fig. is a view in elevation of the cutting tool spindle and bracket therefor as'viewed from the near side of 'the machine illustrated in Fig. 1.

Fig.. 4 is a view in elevation of the same as seen `3o from the right. hand end or Fig. a.

Fig. 5 is a longitudinal verticalsectlonal view of the same, showing the means for raising the rear end of the spindle during the cutting or turning operation, taken on the line 5-5 of Fig. 6 is a view of the same, partly in top plan and partly in horizontal section, showing the relation of the spindle to the pistoneor like work piece being turned. j

4o Fig. l isaview in elevation as s een from the left hand end of Fig. `6. l Y

' Fig. 8 is an enlarged view, partly in top' plan and partly in horizontal section of the forward end of the spindle and a modied form of work 45 holding device with the work piece positioned thereon, showing the relation of th`e axis of rotas tion of the spindle to the axisof the piston being turned.

Fig. 9 is a sectional view taken on the line G-S 50 of Fig. 8, looking in the direction indicated.

' Fig. 10 is a top plan view of a two spindle machine in which both spindles'are belt driven by a single motor.

Fig. 11 is a View .nd of the machine shown in Fig. 10.

4 mounted in ways on the spindle.

. centering diskll is att in elevation of the left'hand three spindles belt driven by two different mof tors and illustrating the odset or echelon posi:

tioning of .the spindles.

Fig. 13 is a view in elevation of the skirt-end elliptical shape thereof.

of a piston: showing the Fig. 14 is a view in side elevation of the same,

showing the tapering toward the head.

of the same from thel skirt Fig. 15 is aside elevation of the piston shown in Fig. 14, rotated 90 the view being taken with the piston about its longitudinal axis with refer. ence' to the position depicted in Fig. 14.

Fig. 16 is an enlarged side elevation of the work holding iixture shown shown mounted thereon.

Fig. 17 is an enlarged vertical section taken in 8.318411 Fig. 416.

a plane through the piston in Fig. 1. a piston being Fig. 18 isa further enlarged end elevation of work piece engaging parts shown in Fig. 17, and

Fig. 19 is a view fled form of work means.

' In theconstruction shown in the drawings, the machine tin general comprises a base support il of substantially rectangular shape and having a reciprocating work holding table i8 slidably holding fixture or support table il for carrying a piston the top I1 is mounted on th thereof. A work Il or like piece o work toward and away from the cutting tool of The base I5 has an inverted `U shaped bridge 20 mounted on laterally projecting shoulders 2l and which supports a tor driven spindle 2l in Fig. 1 of the drawings. `Referring to Figs. comprises'a frame 24 bridge 2l by verticallyheads of which engage formed in the top surface of 2l and is received in and 22 integrally formed thereon horizontally disposed mobly generally designated 2 to 7, the spindle assembly secured to the top10! the disposed boltsy 25. the in inverted T-slots M the bridge 2B. A'

ched to the underside of .the frame 2l at the mi die thereof by cap screw a aperture' 29 formed in the top surface of the bridge 20. The frame 24 may be pivotally swung horizontally about the disk 21 for positioning the frame at .differentangles with respect to the bridge.- 4

The front end of the frame .2l is provided with 'an integrally formed depending lug 30 which is received between the inner ends of axially aligned.

opposed adjusting screws 3l and bosses threaded through lugs or vspectively, rigid on the bridge l2 which are 33 and Il, re- 20. The rear endv a0.l similar to Fig. 1'1 of a modipiece holding and aligning spaced-depending lugs 35 and 36 which are positioned between axially aligned opposed adjusting screws 31 and 38 which are threaded through lugs or bosses 39 and 40'respectively, which are rigidly attached to the bridge 20. All of the adjusting Vscrews are provided with jamb nuts 4I for securing the screws in position when adjusted.

The frame 24 is formed with a relatively flat bottom portion with upstanding sides and at the front end thereof the sides curve toward each other to form an inverted U'shaped portion 42 which imparts rigidity to that end of the frame, the base of the, frame being cut away atthis point and the sides continued forward in advance of the portion 42 to form a pair of spaced parallel axially aligned Vbeering heads 43 and 44.

A generally tubular shaped spindle bracket 45 is pivotally mounted at its forward end between the bearing heads 43 and 44 by trunnions 46 and 41 which pass through the bearing headsand through similar bearing heads 48 and 49 formed on the spindle bracket. 'I'he bracket 45, adja-v cent its rear end, is provided with laterally projecting kscrew studs 50 and 5| which extend into vertically disposed slots 52 and 53 respectively formed in the upstanding sides of the frame 24. The slots 52 and 53 are formed at the lower end of vertically disposed bores formed in the thickcned side walls and in which are contained helical compression springs 54 and`55 which bear between the studs 50 and 5I at their vlower ends` so that the rear end of the bracket is yie1di'ngly urged downwardly at all times.

Means are provided for supporting the rear end of the bracket 45 against the action of, the compression springs and comprise a vertically disposed post 58 slidably mounted-in a sleeve bracket 59 which is rigidly attached to the bridge 20. 'I'he upper end of the upost 58 is axially bored and threaded to receive an adjusting screw 60, the head of which is recessed to receive a ball bearing 6I, which provides rolling contact with the side wall surfaces 62 `f-of an inverted V-shaped groove formed in a bearing block 63 which is' rigidly attached to the spindle bracket 45. Rotative movement of the post 58 is limited by the inner projecting end of a screw 64 which is received in an axially disposed slot 65 formed in the post 58, as shown in Fig. 5.

'I'he lower end of the post 58 isbifurcated to form a pair of spaced parallel arms 66 and 61, between which is journaled a roller or wheel 68 on a pin 89. The wheel or roller 68 rests upon the top surface oi a cam block 10 which is rigidly secured to the table I6 by screws 1I, 12 and 13, the latter two of which pass through angle shaped clips 14 and 15 respectively. The vertical arm of each clip rests on the top of the table I6 a d the horizontal arm of each overlaps the extended marginal edges 16 and 11 respectively, of the cam block 10. 'I'he top surface of the cam plate 10 is sloped as shown at 10A, so as to move the post 58 upwardly and thereby raise the rear end-of the spindle bracket to the position shown in dotted outline (Fig. 5) when the table I6 moves to the left with respect to the stationary bridge 20.

I'he spindle bracket 45 is provided with lspaced axially aligned spindle bodies 18 and 19 rigidly retained therein by clamping bolts 18A and 19A, respectively. The bodies 18 and 19 vcarry special ball bearing assemblies in which is journaled a spindle shaft 8|. le eld 82 and armature 83 of an electric moto are positioned between bracket supporting frame 24 ,f lines ||4 in Fig. 13, to form the spindle bodies 18 and 'I9 within the bracket l45,the armature 83 being carried on and rigidly attached to the spindle shaft 8| for driving the same while the eld 82 is rigidly attached to the bracket 45.

The rear end of the spindle shaft 8| projects from the bracket 45 suiiciently to receive a brake drum 84 which is keyed thereto in the usual man-l ner. The forward end of the spindle shaft 0I is provided with an axially disposedtapered socket 85 for receiving the shank of a cup-shaped cutting tool carrying cage 86, the rim 81 .of Which-is drilled in a' radial direction to receive a cutting tool 88 which is adjusted or positioned in a radial direction by\a threaded plug 89 which abuts against the base end of-the cutting tool. The cutter 88 is also held lby the inner end of the screw 90 which is threaded into rim 81 of the tool holder 86 -in a direction substantially at right angles tothe axis of the cutting tool 88. 'I'he tip or point of the cutting tool 88 is so positioned and arranged as to rotate in a plane which contains the axis ofthe trunnions 46 and 41.

In the modified form illustrated in Figs.8 and rear of the head .9| which is journaled in spaced axially aligned bearings and 96 formed in the f supports ,91 and 98 respectively, and which are formed-on the top surface of a base plate 99.

The underside of the base plate 99 is supported on the table I6, which slides on the ways |0I 4of the base I5. 'Ihe shaft 94, at a point between the spaced bearings 95 and 96, is provided with l a radially extending arm |03, the outer free end4 of winch is lpivoted to oney end of a link 04, the other end of which is pivoted to one end of a horizontally slidable push bar |05. The push bar. |05 is slidably mounted in an upstanding supvporting bracket |06 formed on the top surfaceof the base plate 99. The end thereof opposite to the pivoted link |04 is bifurcated to receive.

a journaled roller |01 which surface |08 formed at the upper end oi' a bracket arm 09, the lower end of which is rigidly secured to the stationary supporting base I5 by bolts ||0.

rides against a cam A helical tension spring ||I has one end at`50 tached to the upstanding bracket |06 and the other end thereof attached lto a depending hook I I2 formed at the extremity lof the arm I 03 for normally maintaining the roller |01 in contact with the cam surface |08.

y In the operation of this device, the spindle is pivotally swung 21 and accurately poadjusting screws 3|, 32, plane ,of rotation of the about the centering disk sitioned by means of the 31 and 38 so'that the cutting tool 88 will be at a predetermined angle with respect to a plane normal to the axis of the piston I9 or other work piece whlch'may be placed on the work holding fixture I1.

The clamping bolts 25 are then tightened so as to rigidly hold the spindle supporting frame in such position. A work holding xture is then ymoved toward the spindle along the axis line` I3, as shown in Figs. 6 and 8, so that the cutting tool, as it engages the end of the piston will, when viewed from a direction normal to the axis of the piston, describe an ellipse, thereby cutting away the material shown by dotted the skirt end of the piston to elliptical shape.

As the work holding xture continues to ad,-

vance toward the spindle,the cam surface 10A will, by engagement" with the roller 68 and through the post 56, ball 6| and bearing block 63, raiseethe rear end of the spindle bracket, thereby changing or varying the plane of rota-l tion of the cutting tool 8'8 in a direction at right thedirection of the axis of the spindle and in land ||6. on ealchof the two opposite sides a direction in a horizontal plane parallel to the axis of the piston, the ,combination ofthe two' movements producing a piston or other work piece elliptical in shape when viewed asin Fig. 13, and generally tapered shape, when viewed as in Fig. 14, by reason of the removal of the materialshown -by the dotted lines ||5 in'Fig. 14 and by the dotted lines ||4 in Fig. 13.

The shape of the pistonis, however, not that of a true frusto-cone, but is elliptical at -any section taken normal 'to the axis of the piston. lThe I majorl axes of such elliptical sections, however,

shift in a rotational direction' by an amount proportional to the angle through which the spin- 'lle axis is swung in a vertical plane about the pivots 46 and 41. Thus the piston, when lfitted to a true cylindrical bore has an outside bearing thereof,-whic h describe upon the surface of the said piston a helix. These lands ||6 are, therefore, not truly axially disposedbutfdue to the way in which they are cut, they are inclined or helical with respectv to the axis 'of the piston, as indicated in Figs. 14 and 15,'the` angle Iof the helix with respect toanaxial direction being 'determined' by the angle of the cam surface 10A are keyed to the protruding ends of--th'e which raisesthe rear end of the spindle.

`In the event this helical angle of the lands is desired to be decreased, eliminated, or increased, use is made, of the modied form of fixture holding head shown in Figs. 8 and 9, the cam surface |08 of which can be arranged to either decrease, increase or entirely eliminate the helix angle of the bearing lands. The ycomparatively narrow helical land provides a wide bearing contact inl the cylinder in which4 the piston is disposed and eliminates localized wear on the cylinderwalls which would occur if the land were axially disposed. The effective support ofthe piston in the cylinder is 'thereby circumferentially increased, while the advantages of a narrow bearing which allows room for expansion` of the piston is retained. y

In the form of, the invention shown in Figs. 10 and 11, two belt driven spindle units |20 and |2| are ganged together on a common base and driven by a single motor |22 which' is rigidly -bolted to the outer. side of the frame or spindle unit |2I, a double belt pulley |23 being provided on the armature shaft of the motor for driving two belts |24 and |25 which passI around pulley wheels |26 and |21 respectively, which spindle shafts m and |29 respectively. i,

The spindle units and |2| are in offset relation to each othe n amountV equal to the angle at.which the spi dle units arev set with respect to the axis of t piston being turned,

- so that the cutters of thetwospindle units will ends of the pistons, the direction of movement of the pistonsv or other Work being along the -lines |30.

' As the pistons or other work are moved into Y engagement with -thecutting tools,` the rearends of the .spindle brackets are cammed upwardly y against the action of helical compression springs |32 inthe same manner as inthe preferred'form of the device shown'in the preceding figures.

In the embodiment -of the invention shown in Fig. 12, three spindles and spindle bodies |40, |4|, |42 are mounted in a single bracket |43 which is pivoted at |44 and |45 to the forwardly I projecting bearings |46 andl |41'of a frame |48.

'It will be noted that the planes of the cuttingl tools |49, |50 and |5I V are at a slight angle with respect to the axis formed by the pivot mountings |44 and |45, instead of the axis being in the plane of rotation of the tools as in the preceding forms, the arrangement being such thatV the axis of the tilting mountings passes through cutting tools.

The spindle shafts jeurnaied '1n-trie bodies im" and |4| protrude from the rear end thereof and are provided with belt pulley wheels to receive drive belts |52 from the motor |56. The spindle shaft of the body |42 is similarlyv driven from a single motor |54 through belts |55.v p

Reference may now be had to Figs. 16, 1'? and 18, which illustrate more in detail the construction of the work holding fixture I1. 'I'he upper larged cylindrical boss portion provided with a horizontally disposed bore |6| hushed at |62 and in 4which is received a horizontally reciprocable plunger |63. The inner or left hand end of `plunger |63 is provided with an enlarged head portion |64 in which is formed a partially spherical seating surface |65 cooperable with a correspondingly shaped bearing surface |66 of a swivelled work engaging element |68. Spaced lugs portion of the fixture |1 is provided with an en- |61 are provided upon the work engaging face |68 is provided with a step bore |13 through which projects, in spaced relationfrom the walls thereof, a stud holt |14. A? spring |15 is arranged in compressed condition between the head of the stud bolt |14 and a radially inwardly directed ange |16 provided on the swivelled element |66 'so as yieldably to urge the swivelled element |60 into contact with the enlarged head portion |64 of the plunger |63. This urges the spherical surface bearing surfaces |65 and |66 into close lcontact at all times to prevent admission of dirt or other foreign. matter between the swivelled element and the head portion |64. The plunger |63, its enlarged head portion|64 andthe swivelled element |68fprovide a movable clamping element for retaining the piston I9 secured'to the fixture |1.

The head portion mis provided 'with e recess' on adapter opening to the left from the head e portion and shaped so as to receive the peripheral lsurface of the work piece at the right hand end axis in a predetermined position with reference to the fixture I1. A stationary vclamping element I8I provided with a radially inwardly directed .ange |82 is secured to the xture I1. 'I'he flange |82 is of U-shaped form.` as indicated in Fig. 18, and is adapted to be received within a ring groove |83 of piston I9 or in a similar peripheral groove within the work piece to be turned.

'I'he plunger |63 may be actuated toward and away from the stationary clamping :dange |82 by means of the manually operated crank |84, illustrated in Fig. 1. The operating connection between the manual actuated crank |84 and the plunger |63 may be in the form of a screw, hydraulic means, or any other desired type of actuating means commonly employed in the art. The specic actuating means is not illustrated in the present instance, since the particular type of actuating means used forms no part of the present invention.

In mounting a piston I9, or' similar work piece, upon the fixture I1, the work piece is slid downwardly with the flange |82 of the stationary clamp I8I disposed within the peripheral ring groove |83 ofthe piston I9 or similar work piece and the swiveled clamping element |68 brought into engagement'with the adjacent end face oi the work piece. The spaced work engaging lugs |61 upon the swiveled clamping element |68 upon movement of the plunger |63 in-the directionV indicated by the arrow |85 of Fig. 17 bring the head end wall ofthe groove |83 into firm engagement with the fiange |82 to secure the desired alignment of the piston I9 with reference, to the fixture I1. The recessed adapter |88 upon the enlarged head end portion |64 of plunger |63 of the movable clamping element maintains the longitudinal axis of the piston I9, or similar work piece, in a desired predetermined position with reference to the fixture I1. I'he element |68 is free to swivel relative to the enlarged head portion |64 a suilcient amount so that the surface of the work contacting the lugs |61 does not have to be accurately machined or aligned with reference to the groove face |83. The piston I9, or similar work piece is heldvclamped to the iixture I1 in the position indicated in Figs. 16 and 17, while the work piece is turned to the desired 'shape and then may be removed from the fixture by retracting the plunger I 63 in a direction opposite to that indicated by the arrow |85 in Fig. 11.

The'work piece may then be lifted in a vertical direction out of the clamping means secured to the fixture I1.

Reference may now be had to Fig. 19 in which a slightly modiiied form of movable clamping member and adapter is employed. In this embodiment a iixed clamping member 2I8I is secured to the fixture I1 and providedwith" a substantially -U-shaped iiange |82 adapted to engage a ring groove or similar peripheral groovev |83 of the work piece. A reciprocable plunger 263 is mounted within a bushing |62 pressed within the bore I6I of the upper enlarged portion' |68 of the xture I1. An enlarged head portion 264 is provided on the plunger 263 in much the same manner as in the embodiment previously described and a swivelled element 268 and the head portion 264 are provided with partially spherical bearing portions as before. Swivelling movement of the element 268 with reference to the enlarged head portion 264 is limited by a plurality of stud screws 218, three iii number being preferably employed, and arranged in the relation indicated .'Spaced work engaging lugs 261 are provided on the swivelled element 268, as before.

The adapter for `aligning the longitudinal axis of the work piece or piston I9 in this embodiment takes the form of a reciprocable center 288 mounted within a bore 299 provided at the inner or left hand end of the plunger 263. A spring 29| is arranged ln compressed condition between the bottom of the bore 298 and the outer or right hand end of the reciprocable center 288 for forcing the latter outwardly to project a point 292 within a suitable axially arranged opening 294 within the workpiece or piston I9. An axially arranged groove 295 is provided in the periphery ofthe reciprocable center 288 and a stud screw 296 'cooperates therewith for preventing of the center 288 from the plunger 263.

' The operation of this work holding means is essentially the same as that described with reference to Figs. 16 to 18, inclusive, with the exception of the fact that thespring urged center 288 is employed for maintaining the longitudinal axis of the work piece I9 in the predetermined position vwith reference to the iixture I1 instead of an adapter such as |88 employed in the embodiment shown in Figs. 17 and 18'to engage the peripheral margin of the head end of the work piece.

Although several diierent embodiments of this f invention have been herein shown and described, it will be understood that numerous details of the constructions shown may be altered or.

omitted without departing from the spirit of this invention as dened by the following claims.

We claim:

1. In a machine for shaping or turning an apprdximately cylindrical-piece of work, a support, a work holding device on said support, a device on said support having a cutting tool journaled to rotate in a plane about an axis so as to circumscrib a generally circular area, meansfor moving one of said devices toward the other for engaging the work and cutting tool, said cutting tool's axis of rotation being at an angle to the direction oi.' relative movement of said devices and intersecting with the longitudinal axis of the work piece in such plane.

2. In a machine for shaping or turning an approximately cylindrical piece of work, a support, a work holding device on said support, a spindle device on said support, a cutting tool rotated by said spindle in an orbit about the axis of the spindle so as to circumscribe a generally circular area, means for moving one of said'devices toward the other for engaging the work and cutting tool, the plane of orbital movement of said cutting tool being at an angle -to a plane normal to the direction of r ative movement of said devices and the cente of -said area coinciding with the longitudinal of the work piece.v

3. In. a machine forshaping4 or turning a pieceof work, a support, a work holding device on said support. a device on said support having a cutting ,tool journaled to'rotate in a plane about an axis,

means for moving one of said'devices toward the other for engaging the work and cutting tool, said cutting tool's axis of rotation being at an angle to the direction of relative movement of said devices and means forv changing the plane of rotation or said cutting tool during the period engagement with the work. y

' 4. In a machine for shaping or turning a piece of work, a support, a. work holding device on said support, a device on said support having a .cutting tool journaled to rotate in a plane about an axis, means for moving one of said devices toward' the other for engaging the work and cutting tool,

said cutting tools axis of rotation being at an angle to the direction of relative movement oi said devices, and means i019 progressively changing the plane of rotation oi said cutting tool during the period of engagement with the work.

5. In a machine for shaping or turningv a piece of work, a support, a work holding device on said diierent from they rst mentioned angularv di vergence.

6. In a machine for shaping or turning a piece o! work, a support, a workholding devicel on Y said support, a device on said support having a cutting tool journaled to rotate in a plane about an axis, means for moving one of said devices toward the other for engaging the work and cutting tool, said cutting tools axis of rotation being-at an angle to the direction of relative movement of said devices, and means for moving the, axis of rotation of said'cutting toolat an angle to the-direction of ,relative movement of said'devices during such relative movement but in a direction substantially at right anglesto the first mentioned angular divergence.

' '7. In a machine for shaping or turning va piece i of work, a support, a work holding device on' said support, a device on said support having a cutting tool journaied to rotate in a plane about an axis,

means ior-"movingroneof said devicesitowardfthe other for engaging the work and cutting tool, said cutting tools axis oi' rotation being at an angle tothe direction of 4relative movement of said devices, and means for moving the axis'oi rotation of said cutting tool at an angle to the direcltion of, relative movement oi said devicesduring such relative movement butin a direction kdit-v vferent `from the first mentioned angular divergence, and means for imparting limited rotation l to the work being shaped during the shaping operation. y

8. In a machine for shaping or turning a piece o! work, a support, a work holding device on said support, a device on said support having a cutting` tool journaled to rotate in a plane about an axis,

, means for moving one oi said .devices'towardthe other for vengaging the work and cutting tool,

said cutting tools axis oi' rotation being atan angle to the direction o! relative movement of said devices, means for movingfthe axis of rotation of said cuttingl tool at an angle to the direction of relative movement of said deviceaduring such relative movement but in a `directi'rn diii'erent from the rst mentioned angular diverf gence, and means for imparting, limited rotation I to the4 work being shaped on an axis parallel to the direction of relative movement o! said device,

" during such relative movement.

9. vIn a machine for shaping-or turning a piece of work, a support, a work holding device on said support, a spindle device pivoted to said support, a cutter rotated by saidgspindle in a plane containing the axis of said spindle pivot, means for moving one of said devices relative to the other for engaging the work'and cutter and means for movingy said spindle device on its pivot during such relative movement.

10. In a machine qfor shaping or turning a piece of work, a support, a work holding device on said support, aspindle device pivoted to said support,

l a cutter rotated by said spindle in a plane containing lthe axis of said spindle pivot, means for movingone of said devices relative tothe other for engaging the work and cutter, the plane of rotation of said cutter beingv t an angle to a plane normal to the direction of'such movement, and means for moving said spindle device on its pivot during such relative movement.

11. In a machine for shaping or turning a on said support, a spindle device pivoted to said support, a. cutter rotated by said spindle in a plane Icontaining the axis of said spindle pivot -and perpendicular to the axis of rotation of said spindle, means for moving' one of said devices relative tothe other for engaging the work and cutter, the axis of saidtspindle being positioned at an angie to the directiono! relativemovement of said devices and in a plane containing the axis lof said spindle pivot, and means for moving said spindleV on its pivot. during such relative movement.

12. In a machine for shaping `or turning a` piece of work, a support,.a work holding device on said support, a spindle device pivoted to said support, a cutter rotated by said spindle in a plane perpendicular to the axis of rotation of said spindle and containing the axis of said spindle pivot,means for moving one of said devices relative to the other for engaging the work and cutter -and means for moving said spindle on its pivot during such relative movement.

-. 13.. In a machine for shaping or turninga piece of work, a, support, a work holding device on said support,l a spindle device gpivoted to said support, the axis of-said pivot being'perpendicularto the axisof rotation of said spindle, a cutter rotated by said spindle in aplaneperpendicular to the'axis of rotation of said spindle and containing the axis of said spindle pivot, means tor piece of work, a support, awork holding device,

moving one of saiddevices relative to the other v for engaging the work and cutter and means vfor moving said spindle on its pivot during such rela tive movement.`

14. In a machine forshaping or turning a piece otlwork, a support, a ,work holding device spindle, means forv moving one-oi said devices fon said support, a spindle device pivoted to said*v 1 support. a cutting tool rotated by said spindle in'` a plane normal to the axis of rotation of .saidl relative tothe other for engaging the work and cutting tool, lthe axis ofrotation of said spindle being at an angle to the direction of relative movement or said devices and in a directionparallel to a plane'containing the axis of rotation o! said spindle and theaxis of said pivot 15. In a. machine for shaping orNturning apiece of work, a support,''a work holding device on said support, a spindle device pivoted to vsaid.

support, a cutting tool rotatedby saidsplndle in a plane normal to /the axis of rotation oi said spindlemeans -for moving one of said devices relative to the other for engaging the work and cutting tool, the axis of rotation of said spindle being at an angle to the direction of relative -movement ofA said devices and in a direction parallel to a plane containing the axis of rotation of said spindle and the axis of said pivot mounting and means for moving said spindle device on its pivot during such relative movement.

16. In a machine tool, a base having a stationary support and a movable support thereon, a 104 work holding ilxturemounted on said movable support for supporting a generally cylindrical work piece with the longitudinal axis ci.' said work piece disposed parallel to the direction of movement of said movable support, a single-point tool. a tool spindle mounted on said stationary support for rotating said single-point tool about the axis of said spindle, means for rotating said spindle, the longitudinal axis of said work piece and the axis of said spindle beingdisposed at an angle .and intersecting at the center o! the path of tool rotation, and means for causing relative movement of said movable support with respect to the tool whereby said tool will generate an elliptical surface of said work piece. Y 17. A machine for providing a work piece wit an elliptical surface which comprises means for holding the'work piece substantially against rotation, a single-point tool 4adapted to engage the' work piece, means for rotating the tool, and means for advancing the `,tool and 4work piece relative to each other with the path of relative movement directed at an acute angle to the plane of tool rotation. I 18. A machine for shaping a work piece initially of generally cylindrical shape to provide an elliptical surface, which comprises means for holding the work piece substantially against rotation, a single-point tool adapted to engage the work piece. means for rotating the tool, and means for relatively advancing the work piece and tool to cause the tool to engage the work piece `progressively along the latter with the longitudinal axis of the work piece progressively during such movement coinciding with the center of the area defined by rotation ofthe tool point, but

with such axis directedat an acute angle to ther plane of tool rotation.

19. A machine for shaping a work piece initially'of generally cylindrical shape to provide an elliptical surface; which comprises means for holding the work piece substantially against rota- 

